Derivative Instruments (Schedule Of Notional Amounts Of Derivatives Outstanding) (Details) - USD ($) $ in Millions	Apr. 30, 2016	Jul. 25, 2015
Derivative [Line Items]
Derivatives	$ 13,433	$ 15,278
Derivatives designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Derivatives	958	1,201
Derivatives designated as hedging instruments: | Interest rate derivatives
Derivative [Line Items]
Derivatives	9,900	11,400
Derivatives designated as hedging instruments: | Net investment hedging instruments
Derivative [Line Items]
Derivatives	180	192
Derivatives not designated as hedging instruments: | Foreign currency derivatives
Derivative [Line Items]
Derivatives	1,925	2,023
Derivatives not designated as hedging instruments: | Total return swaps—deferred compensation
Derivative [Line Items]
Derivatives	$ 470	$ 462